A conventional upright piano is assembled in the manner illustrated in FIG. 1. A pair of right and left end panels g, g having right and left arms f, f fixed thereto are attached to a back structure 3 comprized of a back post assembly body a composed of back posts, upper and lower beams and other members. A soundboard b is attached to the assembly body a, a frame d applied with strings c is attached to the assembly body a, and a key bed h is then bridged between and connected to the right and left arms f, f. A pair of right and left action bracket bases j, j are mounted on and connected to the key bed h, and an action means k is supported on those bases j, j through respective bolts i, i engaged therewith so as to be opposite to the frame d. Dampers and hammers are then attached to the action means k, and a back rail n and a keyboard 0 are provided in their respective positions on the key bed h. Furthermore, the keyboard o is adjusted in height as are other parts, and thereafter casing members (not illustrated) such as an upper front panel, a lower front panel, a top panel, etc., are attached.
The piano thus assembled, however, frequently suffers from problems of alignment of some of the parts. Because the action means k is supported on the key bed h through the action bracket bases j, j an alignment error is caused when the end panels g, g are attached to the back structure e, and another error is caused when the key bed h is attached to the arms f, f of the end panels g, g. After the action means k is attached to the arms f, f of the end panels g, g as mentioned above, adjustments are necessary in order to compensate for the cumulative postional errors, in order that each hammer will accurately strike a corresponding string at a closely determined position. Additionally, since there are many assembling steps from the time when the right and left end panels g, g are attached to the back structure e to the time when the casing members are attached, it is innevitable that these assemblying steps must be carried out in succession, and the probability becomes increasingly great that the coated surfaces of the end panels g, g and other parts may be injured inadvertently with a tool used for the assembling work. Furthermore, it takes a much longer time to manufacture the piano. Additionally, since the end panels g, g with the arms f, f to which the action means k is to be attached must be prepared at an early stage of the assembling process, the production of the piano is slowed and accordingly the production cost becomes high.
It has been previously proposed, for example in Wuest U.S. Pat. No. 844,985, issued Feb. 19, 1907, to support the action means of an automated player piano directly from the metal frame of the piano. While this facilitates accurate positioning of the hammers relative to the strings, it also results in vibrations and other noises produced in the action means being fed directly into the frame, and in turn into the strings, and ultimately into the soundboard via the bridge of the piano, and gives rise to spurious noises in the playing of the piano and a degradation of its tonal quality.